<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
     onload="go()">
  <script>

function go() {
  var f = document.getElementById('f');
  var fm = document.getElementById('fm');
  f.appendChild(fm.cloneNode(1));
}

  </script>
  <filter id="f">
    <feMorphology id="fm" radius="2147483500"/>
  </filter>
  <rect height="28" width="256" filter="url(#f)" />
</svg>
